Designing and building complex systems, such as aircraft, space vehicles, marine vessels, marine platforms such as oil rigs, land vehicles such as automobiles and trucks, and the like, is a complex process that involves several disciplines. For example, typically several years of design, testing, analysis, and systems integration are performed before a complex system is put into operation. Furthermore, before a component, subassembly, or assembly is built, a design for the component, subassembly, or assembly is analyzed.
Such an analysis typically entails generating a mathematical model, such as a finite element model, of the component, subassembly, or assembly. The finite element model is a three dimensional, mathematical definition of a component. The model includes surfaces and exhibits geometric properties, material properties, mass, stiffness, and the like. The finite element model can be subjected to static and dynamic testing. Thus, use of mathematical models such as finite element models greatly reduces time and labor to analyze components over building, testing, and analyzing physical models.
However, generating finite element models of components or subassemblies in complex systems, using currently known methods, is a time-consuming and labor-intensive process. Further, generating finite element models of components in complex systems entails engineering efforts across several disciplines. For example, developing a finite element model for all of the major components for mounting an engine under a wing of a commercial airplane, involves a cross-disciplinary team of loads engineers, stress engineers, designers, and weights engineers.
Typically, engineers from each discipline will develop, from a set of requirements, a preliminary design document. From the preliminary design document, a designer configures a two-dimensional centerline preliminary design drawing. The preliminary design drawing represents definition of lines of a component, but the preliminary design drawing does not represent structure of the component. A designer takes the line definition from the preliminary design drawing and develops structural definition for the component. Structural definition includes assigning properties and materials, and gages. Next, a designer generates surfaces for the component based on the structural definition. Surface generation is a very detailed, time-consuming process.
In a series of manual operations, a modeler takes required information off the structural definition to generate a finite element model of the component. Generating the finite element model includes generating surfaces, structural breaks, and properties and materials for the component.
The surface geometry is transferred from a CAD computing environment to a modeling-computing environment such as UNIX. Because manually generated surfaces typically include flaws, the surfaces are cleaned up. For example, meshing operations in commercially-available modeling software may introduce surface flaws. In most cases, a surface is so flawed that the surface must be re-created.
Each surface is mesh-seeded. If the surface is not corrupted, grid and nodal generation is completed as desired. A limited number assignment to the mesh, that is grid and element numbers, is created.
Property and materials are assigned to the created elements. Mass is evaluated and changed, if desired. Finally, numbering errors are manually modified to allow proper interfacing with other finite element models.
The above process results in just one iteration of each component being modeled. Each model can then be subject to static and dynamic testing, as desired or required. Finally, all the finite element models are integrated into a model of a subassembly or assembly. Integration of the component models involves determining connection points and interface connections. When the component models are integrated into an integrated finite element model, documentation of the model is generated, and the model is released. The above process can take thousands of labor hours and hundreds of manufacturing days, and results in just one iteration of an integrated finite element model.
As a result, a first iteration of an integrated finite element model may not be released until well after a 25% design review and may not be released until a 90% design review. Such a long analysis cycle time introduces program risk and is unresponsive to unanticipated growth of work statements in complex system integration projects. Further, such a process is unresponsive to design changes.
The foregoing examples of related art and limitations associated therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.